The support bracket frame wiper blades (German Patent 15 05 397), which have been widely used for a long time in wiping devices for motor vehicle windshields, have a great structural height, which under the flow conditions existing in front of the vehicle window, especially at a high vehicle speed, promotes the tendency of the wiper blade to lift away from the window. At the very least, this reduces the prescribed contact pressure of the wiper blade on the window so greatly that the wiping quality suffers.
In a known wiper blade (German Patent 10 28 896) that is part of a wiping device, the support element for the entire field swept by the wiper blade is intended to assure the most uniform possible distribution of the wiper blade contact pressure against the window that originates at the wiper arm. By a suitable curvature of the unstressed support element--that is, when the wiper blade is not contacting the window--the ends of the wiper strip, pressed completely onto the window during wiper blade operation, are stressed by the then-stressed support element toward the window, even if the radii of curvature of spherically curved vehicle windows change for every wiper blade position. The curvature of the wiper blade must accordingly be somewhat greater than the greatest curvature measured in the field to be wiped in the window in question. Thus the support element replaces the complicated support bracket construction with two spring rails, disposed in the wiper strip, of the kind used in the conventional wiper blades discussed above. Although this does allow reducing the structural height of the wiper blade, nevertheless the attainable improvement in wiping quality at high vehicle speeds still does not meet the stringent demands made in this respect by some customers. The wiper arm, located above the wiper blade, has proved to be advantageous because it lessens the advantages of the low-height wiper blade.